Archive for the ‘tutorial’ Category

Vomitino is a “tongue in cheek firmware” for the HexBright flashlight.
The word “vomitino”, in italian, means something like “little puker” and was chosen for 2 reasons:

– it follows the -ino desinence tradition, so common in Arduino based projects

– it refers to the fact that the firmware implements a “stroboscopic dazzle mode”, inspired by the LED Incapacitator, a security device that is rumoured be able to stop an hypothetic attacker, inducing vomiting and disorientation.

While I used the same frequency range, the Vomitino lacks some of the features of its original inspirer (i.e. multicoloured light). It’s meant to be just a joke and should not be considered a “self defence tool” at all: in the end it’s just very bright and somewhat annoying strobe light, just like the ones you find in disco 🙂
If you’re interested in the original device, go check Lady Ada’s complete replica. If you’re curious, but don’t want to invest too much time and money into it, you can grab my humbler version on github and flash it on your HexBright.

Keep in mind that some people have weird reactions to flashy lights, some simply do not like them and I’m not responsible if you nag poeple with my code 🙂

A few weeks ago I met a young designer interested in digitally augmented mirrors: in particular he was interested in messing with people faces. Since this is the kind of stuff I have some experience with, we ordered a couple drinks and brainstormed about how he could do this and that.
I ended up writing a little demo showing how to easily change parts of people’s face in realtime and, since I think it could be helpful for other people too, I wanted to share it and quickly explain how it works.
Basically I track the user’s face with Jason Saragih’s library and create a mesh that can be overlaid on the lower part of the tracker’s face mesh; then I can use this “partial mesh” to create a UV map from the user’s mouth expression, or to blend a saved mouth expression into the live feed.

You can find the source code on my github and here’s a video showing how it works:

Today I was writing a function to save a specific configuration file from an OF application and I noticed that ofSystemSaveDialog() (the function commonly used to open a save dialog) does not allow me to specify a default save path.

Since I wanted my files saved in a specific location, I quickly wrote a custom function that includes a path argument; it’s super easy and mac only (Objective C ++), but I thought someone could find it useful, so here it is:

Recently a client bought a Kinect to be used with an OpenFrameworks app I wrote for them; we were doing some normal depth tracking, so we did expect a smooth ride, but, after a few seconds from when the Kinect got plugged, the application froze.
To keep it short, it seems that the Kinect model 1473 (the one you’ll find in shops these days) comes with a new firmware that auto-disconnects the camera after a few seconds, causing a freeze whenever you plug it into a computer and try to use it with libfreenect; this of course means that most creative coding toolkits are affected by the problem: I did run into it using ofxKinect, but it will happen also with the libreenect based CinderBlock, Processinglibrary, etc…

Luckily Theo Watson already came up with a solution: you can find a fixed libfreenect here or, if you’re using OF, you can update to the last version on github.
The fix will work also with the Kinect for Windows and, of course, it will not break compatibility with the older 1414 Kinects.
Finally, if you don’t know the model of your Kinect, this picture will explain how to check it out:

Obviously the rgb and depth camera in the kinect need to be calibrated in order to associate the correct pixel with the correct depxel (ok, it’s an ugly neologism, but you know what I mean). Also, every kinect is different so you can’t just take your friend’s calibration data and use it for your device: you have to do the dirty job yourself.

This morning I quickly created a simple program that makes calibration fast and painless It’s OF friendly and based on Arturo‘s code; my code is *DIRTY* ‘cause it’s written in a stream of cosciousness mood while doing 1k other things, but it works good enough, it pops out calibration data in xml format and someone might find it useful, so here it is.